A study of the heart
by hellfox6
Summary: John gets a surprise visit from his second and youngest sister Eva whom he hasn't seen for seven years, who surprisingly enough has the same ability as Sherlock. But this unique beauty has a dark secret that she cant share with anyone. Will she fall prey before she and Sherlock's love can bloom or will it be destroyed with her? Rated M for gore and stuff. sherlock x oc


**I own nothing but really love the BBC Sherlock! And I support Johnlock so don't kill me, please. ."**

I sighed bitterly. Seven years and my annoying, older brother couldn't call me, which was fine. I planed a surprise visit for him. I muttered different conversation starters to myself as I approached the apartment building on Baker Street, trying to remember his address. I believe he said 221B. I carefully knocked on the door, hoping I was correct. "One moment, please." an English-accented voice said. From the sound of it, he was stressed or ill or maybe both. I sighed. Some times I hated my mind, which could pick apart other's lives just at a glance.

The door opened, revealing my blond brother, John Watson, who was several years older then me. "E-Eva?" he asked. I smiled widely at the look of shock on his face. "Hey, Johnny-cakes!" I said playfully, hugging him tightly. "John, who's that?" a much deeper voice said from within the flat. It seemed slightly aggravated toward my brother's absence. "One moment, Sherlock!" John replied to voice, trying to be as kind as possible toward his flatmate who was possibly was the cause of his distress. "May I come in?" I asked in a slightly angered tone, a headache now spreading though my skull. "Yes, please, do come in," John invited, ushering me in so I wouldn't make a scene. I wondered into the flat, my mind instantly absorbing any information it could gather. The skull on the fireplace, the smiley face spray-painted on the wall, violin in the corner, and small kitchen that inhabited body parts - most likely experiments. My eyes fell on a pale man laying on the couch. He looked slightly dead or vampiric. At the least, he had dark curly hair, steel-like grey eyes that held a large amount of intelligence, high cheekbones, a rather scrawny structure and several other things that my brain automatically picked up.

"John, I repeat: who is it?" he questioned in a seemingly irritated tone, looking confused when he saw me instead of my brother. "Hello, Sherlock. My name is Eva Watson. I am John's second sister." I said softly, mentally screaming at myself not to deduce him. He cocked an eyebrow. He sighed once again as he stared at me. I could see his mind at work. The urge suddenly became too much. I had to say something. "Sorry, this is a habit of mine, but you're in your twenties, you most likely have one or two siblings who are older than you and the lot of you have a sibling rivalry. You're extremely intellectual because I can see you mentally picking me apart like I did to you when I walked in. You keep locking your self indoors from others because they are on a lower scale of intellect, you have a bad smoking habit judging from the four or five nicotine patches you have under your shirt, you consider yourself a loner even though you have my dear brother here and if you don't get something extremely complex you mind might come to destroy itself." I managed to say in two breaths.

Sherlock was genuinely shocked at how quickly she picked him apart. He had to admit, it was impressive for a seventeen/eighteen-year-old girl. Even more surprising, she was related to John. He could see small resemblances, but not much. She had semi-long hair the same color of John's, only it was wavy instead of straight, She had strikingly dark blue eyes that reminded him of a stormy sea, she was built a little like John but slightly thinner, she was lovely in normal standards but he wasn't interested in her looks—nope, he wanted to see her brain at work again. "Well then, Miss Watson, may I have the honor of deducing you?" he asked, wanting to blurt out his deductions, but, of course, John told him it was rude and he needed to stop. "I will allow it," she said softly, her eyes darting around the room trying to find things she missed. "You're at least seventeen or eighteen, you have seen a lot of horrors and pain yet it didn't faze you but some injuries like John, and relationships scare you which is reasonable and you're a lot like me," he said lowly. She looked at him and smiled warmly. "Yeah, you got it right, but I didn't expect anything less from the great Sherlock Holmes." she said laughing slightly.

I couldn't help myself it was amusing to see him pick my persona apart but it hurt sort of. I never told anyone that I went to war for two years with John so I could learn how to be a doctor but that didn't work out so well and I left to finish my last two years of collage. "Hey John can I stay a few weeks my dear brother?" I asked sweetly. "I'm afraid not but the flat upstairs is open for rent I'll pay for it till you get a job if you wish other wise I'm afraid you'll have to leave" John said his mood dark and slightly depressing which shocked me. "Alright then my brother if that is the only way to stay then I will do it," I said weakly sighing I really hated it when he twisted my plans around. "My I at least stay the night?" I asked softly fidgeting he sighed, "I suppose you can" he muttered. A sudden buzz from the couch made both of our heads turn to see Sherlock on his phone grinning like a mad man as he read the text. "John murder a few blocks away lets go!" he said excitedly as he slipped a jacket and scarf on. "May I join?" I asked curiously they both looked at each other then at me "I guess just come on otherwise your walking" Sherlock said going out the door. "Is he always like this for murder?" I asked John nodded "you have no idea" he said and we were gone.

I didn't remember much of the car-ride to boring but when we got to the scene I instantly perked up I heard Sherlock do it to. We both quickly hopped out of the car as John paid the nice cabbie that drove us. "Bringing young girls to crime scenes now Sherlock?" a male voice asked. "Oh Anderson please do shut up" Sherlock said he appeared irritated at the man's sudden appearance. "But why?" the man named Anderson asked clearly enjoying making Sherlock mad. "For Christ sake you two grow up Sherlock go to your murder and Anderson I'm 18 years and moving here so please shut up" I said before following my detective, wait mine since when was he mine? I shook my head mentally scolding myself not to get attached to anyone.

"There you are Sherlock and who is this?" an older man asked pointing to me. "I'm miss Eva Watson I recently moved here and I helping Sherlock here and my brother for a school paper," I said lying through my teeth a sweet smile on my lips. "Pleasure I am Lestrade I'm the head of this investigation although I'm not sure that Sherlock is the correct mentor for a young lady like your-self" he said like an overprotective father. "I know mister Lestrade but I wish to be like him someday so please let me trust my judgment sir" I said calmly going to the murder scene.

The victim was a young woman mid-teens with a sniper wound to the head; she wore a faint amount of make-up that was smeared hinting that she tried to remove it; her black blouse and skirt were in a state of disarray probably from the others touching her, her high heel was broken like she stepped on it the wrong way which seemed off seeing how one shoe was gone as well as her purse how did I know she had a purse her various things of make-up was on the ground scattered about and her phone was missing.

"So miss Watson what can you deduce from the scene?" Sherlock said from behind me scaring the holy hell out of me. "She's 16 from the looks of it probably had her first job interview her purse is missing and she was killed with a sniper rifle from a few feet away maybe even from a few inches judging from the splatter marks on the ground" I muttered almost to myself. He nodded in agreement "very well I'll make note of what you just said my dear as well as my own deduction now go home" he said emotionlessly waving his hand never looking at me. I sighed walking home falling asleep on the couch.


End file.
